Add-on slide valve for existing piping

ABSTRACT

The invention comprises a valve stopper which includes, generally, a rubber patch clamp which is used in combination with a slide gate valve assembly, both of which can be added to an existing fluid piping system without shut-down or interruption of flow. The rubber patch clamp first is affixed to the pipe, and then rubber patch clamp and pipe beneath are sawed through with, for example, a hacksaw or other thin blade or carborundum wire blade. As the blade passes through the compressed rubber patch of the clamp, the rubber tends to close around and behind the blade minimizing fluid leakage from the sawn pipe beneath. The pipe is sawn roughly in half, and the blade then is removed. The slide gate of a slide gate valve assembly is extended from its bonnet, extended partly into the sawn slot in the rubber patch clamp and the pipe beneath. Thereafter, the installation is completed by affixing the entire slide gate valve assembly on the pipe, over the rubber patch clamp.

ited States Patent [1 1 Kong [451 July 31,1973

[ ADD-0N SLIDE GATE VALVE FOR EXISTING PIPING Inventor: George M. Long,Hinsdale, 111.

Institute of Gas Technology, Chicago, Ill.

Filed: Apr. 28, 1972 Appl. No.: 248,661

[73] Assignee:

US. Cl 137/15, 137/317, 138/94, 29/l57.1

References Cited UNITED STATES PATENTS 11/1959 Cover 251/327 X 5/1972Chronister 251/327 X Primary ExaminerMartin P. Schwadron e w'ltlliwm'lPeviiB-ieti ve Attorney-Jack E. Dominik, Robert E. Knechtel et al.

[57] ABSTRACT The invention comprises a valve stopper which includes,generally, a rubber patch clamp which is used in combination with aslide gate valve assembly, both of which can be added toan existingfluid piping system without shut-down or interruption of flow. Therubber patch clamp first is affixed to the pipe, and then rubber patchclamp and pipe beneath are sawed through with, for example, a hacksaw orother thin blade or carborundum wire blade. As the blade passes throughthe compressed rubber patch of the clamp, the rubber tends to closearound and behind the blade minimizing fluid leakage from the sawn pipebeneath. The pipe is 8 Claims, 9 Drawim Figures ADD-ON SLIDE GATE VALVEFOR EXISTING PIPING This invention relates to improved stopper valves ofthe slide gate type which can be inexpensively added to existing fluidpiping systems containing fluids under moderate pressures, withoutshutdown or interruption of flow during installation.

The slide-gate or stopper valve of the present invention is primarilyintended for attachment to existing utility gas distribution systemsoperating at 25 psig. or less and in sizes 1% inch through 4 inchnominal pipe sizes. The pipe material may be steel, cast iron, ductileiron or plastic. The design of the stopper valve permits it to beattached to a fluid carrying pipe under pressure, rather than requiringcut-in of an inline body which is characteristic of other valves. Suchcut-in requires isolation of the work section with adjacent valves orstoppers, blow-down and/or drawining to depressurize, purging with inertgases or fluids, or flame control if welding and/or flame cutting is tobe done, cut-in and welding or sleeving of the valve and adjacentflanges or pipe sections, repurging with the primary fluid,repressurization and opening of valves or removal of stoppers, and theneed for a fluid pipe or hose bypass to maintain service beyond the worksection.

There presently exist valves which can stop the flow of fluid in a pipewhen turned off and restore it when turned on. These valves, however,normally include an inline body which is designed to be installed duringinitial construction of a pipe system. If they are to be added to anexisting pipe system, a full cut-in of the type described above isrequired.

There also presently exists leak clamps and sleeves which are adapted tobe attached to existing pipe to prevent the escape of leaking gas orliquid from a damaged or corroded pipe. These leak clamps and sleevesare affixed to the pipes, without disturbing the flow of fluid therein.

There also are presently available stoppers which are designed to beaffixed to a pipe by welding or clamping and, without leaking theprimary fluid, stop its flow temporarily. When installed in pairs, or inconjunction with an existing valve, these stoppers can isolate a sectionof pipe line for, for example, repair or the cutting in of a valve ortee. The price, complexity and configuration of these stoppers, however,preclude their use as a permanent valve. The stopper valve of thepresent invention, on the other hand, combines the function of a valvewith the add-on ability of the stopper, at a price and a simplicitycomparable to the leak clamp. The stopper valve of the presentinvention, therefore, greatly simplifies and reduces the time and costof valve installation. This fact, in turn, makes feasible theinstallation of more valves in existing systems which would provide atleast a two-fold advantage of improving the safety of operations of suchexisting systems by permitting more rapid shutdown of damaged sections,and improve the quality of service by interrupting the supply to fewercustomers via smaller isolated sections.

Accordingly, it is an object of the present invention to provide animproved valve stopper.

More particularly, it is an object to provide improved valve stopperswhich can be inexpensively added to existing fluid piping systemscontaining fluids under moderate pressures, without shutdown orinterruption of flow.

Another object is to provide an improved valve stopper and method foraffixing it to an existing fluid piping system without shutdown orinterruption of the flow in said system.

A still further object is to provide an improved valve stopper whichcombines the function of a valve with the add-on ability of a stopper ata price and a simplicity compared to a leak clamp.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The above objectives are accomplished with the valve stopper and methodof the present invention which includes, generally, a rubberpatch clampwhich is used in combination with a slide gate valve assembly, both ofwhich can be added to an existing fluid piping system without shutdownor interruption of flow. The rubber patch clamp first is affixed to thepipe, and then rubber patch clamp and pipe beneath are sawed throughwith, for example, a hacksaw or other thin blade or carborundum wireblade. As the blade passes through the compressed rubber patch of theclamp, the rubber tends to close around and behind the blade minimizingfluid leakage from the sawn pipe beneath. The pipe is sawn roughly inhalf, and the blade then is removed. The slide gate of a slide gatevalve assembly is extended from its bonnet, extended partly into thesawn slot in the rubber patch clamp and the pipe beneath. Thereafter,the installation is completed by affixing the entire slide gate valveassembly on the pipe, over the rubber patch clamp. If the valve stopperis installed below grade, a valve box is set and the excavationback-filled. The valve box pennits the valve stopper to be operated fromthe surface, by means of a valve key.

The invention accordingly comprises the several steps and the relationof one or more of such steps with respect to each of the others and theapparatus embodying features of construction, combination of elementsand arrangement of parts which are adapted to efl'ect such steps, all asexemplified in the following detailed disclosure, and the scope of theinvention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings in which:

FIG. 1 is a side plan view of a rubber patch clamp exemplary of such arubber patch clamp which can be used with the valve stopper of thepresent invention;

FIG. 2 is a top plan view of the rubber patch clamp of FIG. ll;

FIG. 3 is an end plan view of the rubber patch clamp of FIG. 1;

FIG. 4 is a similar end plan view of a rubber patch clamp exemplary ofan alternate construction which can be used;

FIG. 5 is a perspective view generally illustrating the manner in whichthe rubber patch clamp is affixed to a pipe, and the latter is sawn toprovide a slot therein;

FIG. 6 is a partial sectional view generally illustrating the pipe andthe rubber patch clamp after they have been sawn;

FIG. 7 is a side plan view illustrating the slide gate valve assemblyaffixed to the pipe, over the rubber patch clamp;

FIG. 8 is an end plan view illustrating the sliding gate valve assemblyaffixed to the pipe, over the rubber patch clamp; and

FIG. 9 is a top plan view of the sliding gate valve assemblyillustrating the latter affixed to the pipe.

Similar reference characters refer to similar parts throughout theseveral views of the drawings.

Referring now to the drawings, in FIGS. 1-3 there is illustrated arubber patch clamp 10 exemplary of the type which can be used incombination with a sliding gate valve assembly 40 (FIGS. 7-9) to formthe valve stopper of the present invention. The rubber patch clamp 10includes a clamp portion 11 in the form of an elongated, narrow strip ofsheet metal of a length which will permit the rubber patch clamp to besecured tightly about the peripheral surface of a pipe to which thevalve stopper is to be affixed. A compressed rubber patch 12 ofsubstantially the same width as the clamp portion 11 is adhesively orotherwise afiixed to the clamp portion 11, and is further securedthereon by means ofa pair of laterally extending flanges 14 and 15 onthe clamp portion 11 which are folded to overlie the rubber patch 12, inthe manner which can be best seen in FIGS. 2 and 3. This rubber patch 12underlies a portion of the clamp portion 11 to extend at least about onehalf the circumference of the pipe when the rubber patch clamp 10 isaffixed to the latter. The terminal ends of the clamp portion 11 haveapertures 16 formed therein for receiving a threaded bolt and nut 17 tofixedly secure the rubber patch clamp 10 tightly about a pipe, in themanner illustrated in FIG. 5, wherein the rubber patch clamp 10 is shownsecured or clamped about a pipe 20.

After having affixed the rubber patch clamp 10 about the pipe 20, thenext step in the method of the present invention for afflxing the valvestopper to a pipe is to saw a slot through the rubber patch clamp 10 andthe pipe 20 with, for example, a hacksaw 22 or other cutting meanshaving a thin cutting blade such as the hacksaw blade 23, a carborundumblade or the like. If a blade such as the hacksaw blade 23 is used tocut the slot, the blade sides advantageously can be lubricated withglycol or other rubber lubricants to permit the blade to more easilypass through the compressed rubber patch 12, the latter tends to closearound and behind the hacksaw blade 23 minimizing fluid leakage from thesawn pipe beneath.

As indicated above, the valve stopper is primarily intended forattachment to existing utility gas distribution systems operating at 25psig. or less, and in pipe sizes, within a range of 1% inch through 4inches. In such applications, the rubber patch 12, during the time thatthe slot is sawn into the pipe and after the saw blade is withdrawn issufficiently resilient and compressible to close the slot to minimizeleakage.

In certain applications, particularly with pipes larger than 4 inches indiameter, it may be desirable to use a rubber patch clamp 25 of theconstruction shown in FIG. 4. This rubber patch clamp 25 is generally ofthe same construction as the rubber patch clamp 10, however, it featuresa side follower semi-ring to control the degree of compression of therubber and its pre-formed slot. This semi-ring is forced against therubber by setscrews threaded through the side wall 28.

In FIG. 6, a slot 38 is shown cut in the pipe 20 and in the rubber patchclamp 10. The slot 38 extends at least half way through the pipe 20 topermit a sliding gate valve 42 of the sliding gate valve assembly 40 toextend into the pipe 20 to cut off the passage of fluid therein, in themanner described more fully below.

The sliding gate valve assembly 40 is shown in FIGS. 7-9, and it can beseen to include a top or bonnet portion 41 in which is retained thesliding gate valve 42 thereof. The sliding gate valve 42 is in the formofa thin flat gate or blade 43 which is affixed to one end of a stemportion 44 extending through the top of the honnet portion 41. A handle45 is affixed to the opposite end of the stem portion 44, for operatingthe sliding gate valve 42. The sliding gate valve 42 can be of thepush-pull or screw-shaft type and, in the case of the larger size valvestoppers and pipe sizes, a screw-shaft type preferably is used. Inaffixing the sliding gate valve assembly 40 to the pipe 20, the slidinggate valve 42 is extended or lowered sufficiently to permit its end tobe inserted into and through the slot sawn in the rubber patch clamp 10and the pipe 20, when the top or bonnet portion 41 of the valve assembly40 is seated on the pipe 20. The valve assembly 40 then is securelyaffixed to the pipe 20 by clamping its lower portion 46 about theunderside of the pipe 20, and securing the bonnet portion 41 and thelower portion 46 together by means of fastener means such as thethreaded bolts and nuts 49 extended through apertures (not shown) formedin the lateral flanges 47 and 48 on the respective portions thereof.

The sliding gate valve assembly 40 preferably is proportioned to fitover the rubber patch clamp 10 so that the latter is secured therein andit is not necessary to remove it before installing the sliding gatevalve assembly 40. The valve assembly 40, of course, fits tightly aboutthe pipe 20 so that its interior is sealed by gaskets or 0-rings toprevent leakage.

If the valve stopper of the present invention is installed on a pipebelow grade, a valve box of standard construction is set about it, andthe excavation then is back-filled. The valve box permits the valvestopper to be operated from the surface, by use of a properly made valvekey which will engage with an operating nut or the like replacing thehandle 45 to turn the sliding gate valve 42 or to move it up and down ifit is of the push-pull type.

As the sliding gate valve 42 of the sliding gate valve assembly isoperated, the sliding gate valve is extended through the slot formed inthe rubber patch clamp 10 and the slot 38 fonned in the pipe 20, untilits terminal end engages the opposite interior surface of the pipe, ascan be best seen in FIG. 8. The terminal end of the slide gate valve 42is contoured to permit it to seat flush against the pipe, to completelyblock off flow of fluid through the pipe 20.

From the above description, it can be seen that the valve stopper of thepresent invention can be inexpensively added to an existing fluid pipingsystem without shutdown or interruption of flow. The valve stoppertherefore greatly simplifies and reduces the time and cost of valveaddition and, this factor makes it feasable to install more valves inexisting systems. By installing more valves, the safety of operation ofthe systems can be greatly improved by permitting more rapid shutdown ofdamaged sections. Furthermore, with a larger number of valves installed,the quality of service can be improved since the supply to fewercustomers will be interrupted, since smaller sections of the system canbe isolated.

The stopper valve also can be adapted for automatic operation by certainmodifications and the addition of a topworks consisting of a diaphragm,piston or other similar device. The valve then would serve the functionsof 1) an emergency shutoff, operated remotely or automatically; 2) aflow limiting restriction similarly operated; or 3) a pressure reducingmonitor regulator to be installed ahead of existing pressure regulatorsto meet current safety requirements.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained andcertain changes may be made in carrying out the above method and in theconstruction set forth. Accordingly, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

Now that the invention has been described, what is claimed as new anddesired to be secured by Letters Patent is:

l. A valve stopper for use with a pipe containing a fluid under moderatepressure comprising, in combination: a rubber patch clamp secured to andextending about the peripheral surface of said pipe, said rubber patchclamp closing around and behind a thin cutting blade means as the latteris used to cut a slot in said pipe to minimize fluid leakage from saidslot, a slide gate valve assembly including a valve top portionsupporting a movable slide gate of a thickness and configuration toextend through said slot into said pipe and to block passage of fluidthrough said pipe when disposed therein and a valve bottom portion, saidvalve top and bottom portions being formed to permit said movable slidegate to be extended partially into and through said slot to locate saidmovable slide gate therein and to be clamped together about said pipewith said rubber patch clamp enclosed therein, and means for movablyoperating said slide gate to extend it through said slot in said pipe tocut off the flow of fluid therein.

2. The valve stopper of claim I, wherein said rubber patch clampcomprises a sheet metal covered compressed rubber patch clamp.

3. The valve stopper of claim 2, wherein said compressed rubber patchportion of said rubber patch clamp extends about at least one-half theperipheral surface of said pipe, and wherein said slot extends aboutapproximately one-half the peripheral surface of said pipe.

4. The valve stopper of claim 2, wherin said sheet metal coveredcompressed rubber patch clamp has a pre-sawn slot in the metal portionthereof.

5. The valve stopper of claim I, wherein said movable slide gate of saidslide gate valve assembly comprises a push-pull slide gate.

6. The valve stopper of claim 1, wherein said movable slide gate of saidslide gate valve assembly comprises a screw shaft type slide gate.

7. A method of installing a valve stopper on a pipe containing a fluidunder moderate pressure comprising the steps of: afi'lxing a rubberpatch clamp about said pipe, sawing a slot through said rubberpatch'clamp and through said pipe, said rubber patch clamp closingaround and behind the saw blade and minimizing fluid leakage from thesawn pipe beneath, withdrawing the saw blade from said pipe and saidrubber patch clamp, extending the slide gate of a slide gate valveassembly through said slot and partially into said pipe, and securingsaid slide gate valve assembly about said pipe and said rubber patchclamp, whereby said slide gate can be operated to extend it through saidslot and into said pipe to stop the passage of fluid therein.

8. The method of claim 7, further including the steps of setting a valvebox about said stopper valve, whereby said stopper valve can be operatedfrom the surface of the ground through said valve box with a valve key,and

backfilling about said pipe and valve box.

1. A valve stopper for use with a pipe containing a fluid under moderatepressure comprising, in combination: a rubber patch clamp secured to andextending about the peripheral surface of said pipe, said rubber patchclamp closing around and behind a thin cutting blade means as the latteris used to cut a slot in said pipe to minimize fluid leakage from saidslot, a slide gate valve assembly including a valve top portionsupporting a movable slide gate of a thickness and configuration toextend through said slot into said pipe and to block passage of fluidthrough said pipe when disposed therein and a valve bottom portion, saidvalve top and bottom portions being formed to permit said movable slidegate to be extended partially into and through said slot to locate saidmovable slide gate therein and to be clamped together about said pipewith said rubber patch clamp enclosed therein, and means for movablyoperating said slide gate to extend it through said slot in said pipe tocut off the flow of fluid therein.
 2. The valve stopper of claim 1,wherein said rubber patch clamp comprises a sheet metal coveredcompressed rubber patch clamp.
 3. The valve stopper of claim 2, whereinsaid compressed rubber patch portion of said rubber patch clamp extendsabout at least one-half the peripheral surface of said pipe, and whereinsaid slot extends about approximately one-half the peripheral surface ofsaid pipe.
 4. The valve stopper of claim 2, wherin said sheet metalcovered compressed rubber patch clamp has a pre-sawn slot in the metalportion thereof.
 5. The valve stopper of claim 1, wherein said movableslide gate of said slide gate valve assembly comprises a push-pull slidegate.
 6. The valve stopper of claim 1, wherein said movable slide gateof said slide gate valve assembly comprises a screw shaft type slidegate.
 7. A method of installing a valve stopper on a pipe containing afluid under moderate pressure comprising the steps of: affixing a rubberpatch clamp about said pipe, sawing a slot through said rubber patchclamp and through said pipe, said rubber patch clamp closing around andbehind the saw blade and minimizing fluid leakage from the sawn pipebeneath, withdrawing the saw blade from said pipe and said rubber patchclamp, extending the slide gate of a slide gate valve assembly throughsaid slot and partially into said pipe, and securing said slide gatevalve assembly about said pipe and said rubber patch clamp, whereby saidslide gate can be operated to extend it through said slot and into saidpipe to stop the passage of fluid therein.
 8. The method of claim 7,further including the steps of setting a valve box about said stoppervalve, whereby said stopper valve can be operated from the surface ofthe ground through said valve box with a valve key, and backfillingabout said pipe and valve box.